POS1511 PERSISTENCE OF RENAL-EXTRARENAL REMISSION AND EFFECT ON RISK OF SLE FLARES AND OF CHRONIC KIDNEY DISEASE IN PATIENTS WITH LUPUS NEPHRITIS
Authors: G. Moroni, M. Gatto, G. Frontini, M. Calatroni, S. Quaglini, F. Reggiani, B. Trezzi, L. Iaccarino, R. A. Sinico, A. Doria
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> How renal and extrarenal remission affects risk of flares and of chronic kidney damage (CKD) development in systemic lupus erythematosus (SLE) patients with active lupus nephritis (LN) was not clearly disentangled. <h3>Objectives</h3> To investigate the effect of maintained or interrupted renal-extrarenal clinical remission on the risk of SLE flares and CKD development in LN. <h3>Methods</h3> We conducted a retrospective cohort study on biopsy-proven LN patients in whom we evaluated i) the probability of achieving and maintaining renal-extrarenal clinical remission; ii) the impact of renal-extrarenal clinical remission on the risk of SLE flares and CKD development (defined as serum creatinine &gt;1.0mg/dl with eGFR &lt;60ml/min/1.73 m2 and inactive urinary sediment, confirmed by at least three determinations for at least 3 months); iii) the predictors of renal-extrarenal clinical remission. Renal-extrarenal clinical remission was defined as serum creatinine &lt;1mg/dl, eGFR&gt;60ml/min/1.73m2, proteinuria &lt;0.5g/24h and cSLEDAI=0 lasting for at least one year. Time to renal-extrarenal clinical remission, the likelihood of its maintenance and the risk of SLE flares were estimated through Cox regression. <h3>Results</h3> 303 patients were included in the study. Over a 14.8-year-follow-up, 46 patients never achieved while 257 achieved remission after a median of 1.44 (0.69-3.58) years from initial therapy for LN. In 142 out of 257 patients, remission ended after a median of 3.6 (2.30-5.90) years due to SLE flares. 115 patients maintained an uninterrupted remission for 9.5 (5.8-14.5) years. At multivariate analysis, age &gt;40 years (OR95%CI: 1.017 (1.005-1.028); p=0.004), hydroxychloroquine use (OR95%CI:1.384 (1.109-1.661); p=0.021) and absence of arterial hypertension (OR95%CI: 0.699 (0.425-0.975); p= 0.011) were independent predictors of renal-extrarenal clinical remission. CKD occurred in 56% of patients who had never reached renal-extrarenal clinical remission, in 21.8% of those who lost remission due to SLE flares and in none of those who maintained remission permanently (p&lt;0.0001). Five, 10 and 15 years after the beginning of renal-extrarenal clinical remission 63%, 47% and 38% of patients respectively were still in remission. After the 15<sup>th</sup> year from the start of renal-extrarenal clinical remission, no patient developed SLE flare and remission persisted without interruption until the end of the observational period. The risk of SLE flares decreased to 10%, 5% and dropped to 2% on remission lasting&lt;5, 5-10 and 10-15 years respectively. No achievement or loss of renal-extrarenal clinical remission due to SLE flares were associated with CKD development. <h3>Conclusion</h3> Older age, hydroxychloroquine use, absence of arterial hypertension predict remission among LN patients upon initial therapy. The longer the remission, the higher the chance of it persisting uninterrupted, and the lower the risk of SLE flares and of CKD. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Gabriella Moroni Speakers bureau: GSK, Mariele Gatto Speakers bureau: GSK, Giulia Frontini: None declared, Marta Calatroni: None declared, Silvana Quaglini: None declared, Francesco Reggiani: None declared, Barbara Trezzi: None declared, Luca Iaccarino Speakers bureau: GSK, Renato Alberto Sinico: None declared, Andrea Doria Speakers bureau: GSK, Pfizer, AZ, Celgene, EliLilly, BMS, Roche.